1, female (natural length circa 0·2 mm.); 2 _a_, left leg of the first pair of _Phytoptus tristriatus_, and 2_b_, of _Phytoptus tristriatus_ var. _carinea_, magnified 550 times—all after Dr. Nalepa. 3, infested pear leaf.
FIG. 64.—PEAR LEAF BLISTER MITE, PHYTOPTUS PYRI. ]
I am greatly obliged for your kind letter received two days ago, and it is so very good of you to have taken the trouble of writing the names of the various portions of the _Phytoptus_ on your plate accompanying so clearly for me that I hardly know how to express my thanks sufficiently. This is indeed a most acceptable help, for there were some of the quite minutely technical terms that I had failed to make out the meaning of, and now you have most excellently got over my difficulties for me, and I thank you very much for the same. Since I wrote to you at Gmünden I have had great pleasure and benefit in procuring some of your valuable publications, so full of excellent descriptions and figures. One of these is the separate impression of your paper, read on January 24, 1889, with 9 plates, including p. 11, of which you have now sent me this valuably explained copy.
Another—the separate impression for February 13th—contains description, p. 11, and figure, plate iv., of _Phytoptus pyri_, and I have also a copy of your “Genera und Species der Familie Phytoptidæ,” 1891. Now I think, thanks to study of your clear descriptions, I have a fair knowledge of the characteristics of a _Phytoptus_, and of the divisions of the Family Phytoptidæ. When I publish my next Annual Report I should very much wish to give my readers some better information than I have hitherto been able to do, and to point to them from what source I obtained it, and how they may obtain it for themselves. I think I have your kind permission to use one of your figures. I am therefore having a very careful copy executed of your _P. pyri_ (plate IV., fig. 1), of the two claws (in your Genera and Species, plate ii., 9_a_ and _b_), together with an attacked leaf from life (fig. 64).
Your part would be a most soundly valuable aid to readers here, for really and truly I doubt if more than very few among us are aware (say) that the legs of the _Phytoptus_ are made up of claw, tarsus, tibia, and so on, much less that the claw is of this peculiar shape. I confess to you I was ignorant of this myself. I should like to give a part of your description of the _P. pyri_ to show what a description ought to be; also to allude to the species which you were so good as to name for me, and to your principle of classification (p. 317 of “Katalog”). Should any of this not be according to your pleasure, I beg of you kindly to tell me. I should indeed be ungrateful if, after all your kind help, I trespassed on your information against your wish. Should you allow it, you may depend on me to quote accurately, so that my quotations will send readers to your works, not enable them to use my report as a robbery of you; also I would fully and honestly acknowledge the source of my information, and be truly grateful. I wish I could send you specimens. Would you care to have some galls of the _Phytoptus ribis_ from black currant in their (I think) very unusually advanced condition for this time of year? I think I could procure some from Kent.